Lubricating oil thickened to a grease consistency with a mixture of a bispyrazolone and an organophilic siliceous compound



United States Patent Ofiice 2,983,683 Patented May 9, 1961 Joseph J. McGrath, Monroeville, and John P. Pellegrini,

In, Pittsburgh, Pa., assiguors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware N Drawing. Filed July 10, 1959, Ser. No. 826,144 9 Claims. (Cl. 25 2-49.7)

This invention relates to improved lubricating compositions and more particularly to lubricants suitable for high temperature lubrication.

The trend in design of modern aircraft has accentuated the need for greases Which will lubricate anti-friction bearings operating at high rotational speeds and high temperatures. While considerable progress has been made in recent years in, producing improved aircraft greases some difiiculty has been encountered in producing a grease which will effectively lubricate bearings operating at high rotational speeds and high temperatures for prolonged periods of time. Conventional aircraft greases currently available have failed to meet the stringent requirements on such a lubricant.

t We have discovered that a lubricating composition having improved lubricating characteristics for an extended period of time when used to lubricate bearings operating at an elevated temperature under high rotational speeds can be obtained by incorporating into a lubricating oil in oil thickening proportions a mixture of a bis-pyrazolone having the following structural formula:

"o=o 0:041" 11-h 1:0 0:6 1

. y N N l l wherein R is selected from the group consisting of hydrogen, alkyl (e.g., methyl, ethyl, propyl, butyl and pentyl), aryl (e.g., phenyl and naphthyl), aralkyl (e.g., benzyl) and cycloalkyl (e.g., cyclopentyl and cyclohexyl) radicals, R is selected from the group consisting of aryl (e.g., phenyl and naphthyl), aralkyl (e.g., benzyl) and alkaryl (e.g., tolyl) radicals and R" is selected from the group consisting of alkyl (e.g., methyl, ethyl, propyl, butyl andpentyl), aryl (e.g., phenyl and naphthyl) and alkaryl (e.g., tolyl) radicals and a secondary org-ano .philic siliceous oil thickening agent. Thus, theimproved lubricating composition of our invention comprises a dispersion in a lubricating oil of a sufficient amount to thicken the lubricating oil to a grease consistency of a mixture'of a bis-pyrazolone of the type designated by the above structural formula and an organophilic siliceous oil thickening agent. 7

It. will be noted that at least one of the substituents in the above formula must be a carbocyclic radical and that the only substituent which can be hydrogen is the ods of time. The carbccyclic radicals, especially phenyl radicals, are preferred because of the increased resonance or thermal stability contributed to the pyrazolone by the carbocyclic radicals.

The amount of the combined bis-pyrazolone and the organophilic siliceous material which We use is an amount suflicient to thicken the lubricating oil to a grease consistency. In general, this amount comprises about 10 to about 60 percent by weight of the total composition. The weight ratio of the bis-pyrazolone to the organephilic siliceous material will vary depending upon the characteristics desired in the ultimate composition. In general, however, the ratio of the bis-pyrazolone to the organophilic siliceous material is between about 1:1 and about 20: 1.

Bis-pyrazolones within the above general classification are as follows:

4,4'-bis( 1-phenyl-3-methyl-5-pyrazolone) 4,4'bis( l-phenyl-3-ethyl-5-pyrazolone) 4,4-bis 1-phenyl-3-prcpyl 5-pyrazolone) 4,4'-bis(1-phenyl-3-n-butyl-5-pyrazolone) R radical attached tothe nitrogen in the 2 position. It

should b e tftuther noted that whereas the alkyl groups atoms inthe ;a'lkyl portion of the aralkyl and alkaryl can contain from 1 to 5 carbon atoms, the alkyl porradicals-are undesirable in that the thermal stability of the bis-pyrazblbne is deleteriously affected where the lubricant produced therefrom is subjected to a high tem:

perature 'and high rotationalwspeeds over extend'ed peri-' 4,4'-bis( l-phenyl-3-tert-butyl-5-pyrazolone) 4,4-bis l-phenyl-3 -pentyl-5-pyrazo lone) 4,4'-bis( 1-phenyl-3-phenyl-5-pyrazolone) 4,4'-bis( 1-pheny1-3-naphthyl-5-pyrazolone) 4,4-bis( l-phenyl-3-tolyl-5 pyrazolone) 4,4-bis( l-naphthyl-3-methyl-5-pyrazo1one) 4,4-bis 1-naphthyl-3 -ethyl-5-pyrazolone) 4,4'-bis( 1-naphthyl-3-propyl-5-pyrazolone) 4,4'-bis( 1-naphthyl-3-n-butyl-5-pyrazolone) 4,4'-bis 1-naphthyl-3-tert-butyl-5-pyrazolone) 4,4-bis( 1-naphthyl-3-pentyl-5-pyrazolone) 4,4'-bis (r1-naphthyl-3-phenyl-5-pyrazo-lone) 4,4-bis( l-naphthyl-3-naphthyl-5-pyrazolone) 4,4-bis( 1-naphthyl-3-tolyl-5-pyrazolone) 4,4-bis( l-benzyl-3-methyl 5-pyrazolone) 4,4'-bis(1benzyl 3-ethyl-5-pyraz0lone) 4,4'-bis(1-benzyl-S-propyl-5-pyrazolone) 4,4'-bis( l-benzyl-S-n-butyl-5-pyrazolone) 4,4'-bis( 1-benzyl3-tert-butyl-5-pyrazolone) 4,4'-bis(1-benzyl-3-pentyl-5-pyrazolone) 4,4-'bis( l-benzyl-3-phenyl-5-pyrazolone) 4,4'-bis(1-benzyl-3-naphthyl-5-pyrazolone) 4,4-bis l-b enzyl-3-tolyl-5-pyrazolone) 4,4-bis( l-tolyl-3-methyl-5-pyrazolone) 4,4-bis 1-tolyl-3-ethyl-5-pyrazolone) 4,4'-bis(1-tolyl-3-propyl-'5-pyrazolone) 4,4'-bis( l-tolyl-3-n-butyl-5-pyrazolone) 4,4-bis 1-tolyl-3-tert-butyl-5-pyrazolone) 4,4'bis( 1-tolyl 3-penty1-5-pyrazolone) 4,4-bis(1-tolyl-3-phenyl-'5-pyrazolone) 4,4'-bis( l-tolyl-3-tolyl-5-pyrazolone) 4,4'-bis( l-phenyl-2,3-dimethyl-5 pyrazolone) 4,4-'-bis( l-phenyl-2,3 diethyl-5-pyrazolone) 4,4'-bis(i1-phenyl-2,3-dipropyl-5-pyrazolone) 4,4'-bis( l-phenyl-2,3-di-n-butyl-5-pyrazolone) 4,4'-bis(1-phenyl 2,3-di-tert-butyI-5-pyrazolone) 4,4-bis( 1-phenyl42,3 -dip entyl-S -pyrazolone) 4,4'-bis( l-phenyl-Z,3diphenyl-5-pyrazolone) 4,4'-bis(1-phenyl-2,3-dinaphthyl-5-pyrazolone) 4,4'-bis 1-phenyl-2-benzyl-3-methyl-5-pyrazolone 4,4'-bis( l-phenyl-2-cyclopentyl-3-methyl-'5-pyrazolone) 4,4'-b-is( 1-phenyl-2-cyclohexyl-S-methyl-S-pyrazolohe) 4,4'-bis l-phenyl-2-methyl-3-ethyl-5pyrazclone) 4,4.-bis( l-phenyl-2-methyl-3-propyl 5-pyrazolone) 4,4'-bis('1-phenyl-2-methy1-3-tert-buty1-5epyrazoloue) 4, 4-bis(1-phenyl-2-methyl-3-pentyl-5-pyrazolone) 4,4-bis(i1-phenyl-2-methyle3phenyl-Spyrazolone) 4,4'-bis(1-phenyl-2-methyl-3-naphthyl-5 pyrazolone) 4,4'-bis( 1-phenyl 2-methyh3 tolyl-5 -pyrazolone) i cyclic,.,aliphatic, and heterocyclic amines.

.densation of 2 moles of the latter product in the presence of phenylhydrazine under refluxing conditions 'gives 1 mole of 4,4'-bis(1-phenyl-2,3-dimethyl-5-pyrazolone).

The amount of the bis-pyrazolone used may vary over wide limits dependingupon the particular oil with which the bis-pyraz olone is to be blended and upon the properties desired in the final lubricating composition. While 7 as much as 50 percent by weight of the total composi tionmay comprise the bis-pyrazolone, we prefer touse smaller amounts, that is, in the order of about 10 to 40 percent by weight. It should be understood, however, that, depending upon the consistency of the composition desired and upon the organophilic siliceous material used in combination therewith, less than 10 percent or more than 50 percent of the bis-pyrazolone may be employed.

The organophilic siliceous materials which we ,employ in the lubricating composition of. this invention are exemplified by bentonite-organic base compounds known commercially as Bentones and finely divided organosiliceous solids such as the esterified siliceous solids known commercially as Estersils. .The amount of the organophilic siliceous material employed may vary .over wide limits depending upon the particular compound employed, the particular oil with which the siliceous compound is blended and-the properties desired in the ultimate composition. While the organophilic siliceous with a total of at least 10 to 12 carbon atoms.

quaternary ammonium salts. Examples of such amines and salts are: decylamine, dodecylamine, tetradecylamine, hexadecylamine, octadecylamine, hexadecyl ammonium acetate, octadecyl ammonium acetate, dimethyldioctyl ammonium acetate, dimethyldidodecyl ammonium acetate, dimethyldodecylhexadecyl ammonium acetate, dimethyldicetyl ammonium acetate, dimethylhexadecyloctadecyl ammonium acetate, dimethyldioctadecyl ammonium acetate, and the cor-responding chlorides and quarternary ammonium chlorides. The organic bases employed should be such as to impart substantial organophilic properties to the resulting compounds. The preferred bentonite compounds are prepared from quaternary ammonium compounds in which the N-substituents are aliphatic groups containing at least one alkyl gtlilup en aliphatic amines are used they preferably contain at least one alkyl group containing at least 10 to 12 carbon atoms.

While the long chain aliphatic amine bentomte cornpounds are readily dispersible in practically all oil bases, dispersion of the short or single chain aliphatic amine bentonite compounds, in the oil, particularly mineral oils and synthetic oils other than ester lubricants, can be facili-i tated by the use of one or more solvating agents. Suit able solvating agents are polar organic compounds such as organic acids, esters, alcohols, ethers, ketones, andaldehydes, especially low molecular weight compounds of these classes. Examples of suitable solvating agents are:

material may comprise as much as 20 percent by weight 7 of the total composition, we prefer to use smaller amounts,

that is, in the order of aboutl to about 10 percent by weight. It should beunderstood, howeven'that depend.- ing upon the consistency of the composition desired and upon the bis-pyrazolone content of the composition less than 1 percent or more than 10 percent of the. organophilic siliceous material can be employed. Typical bentonite-organic base compounds'employed in accordance with'the invention are compounds comethyl acetate, acetic acid, acetone, methyl alcohol, ethyl alcohol, benzoyl chloride, butyl stearate, cocoanut oil, cyclohexanone, ethylene dichloride, ethyl ether, turf-oral,- isoamyl acetate, methyl ethyl ketone, and nitrobenzene. In cases where the use of a solvating agent is desirable for effecting more rapid and more complete dispersion of the organic bentonite compound in the oil, ordinarily only a relatively small amount of such agent maybe necessary. However, as much as about 50 percentf by weight based on the amount of the bentonite compound can be used.

Typical estersils employed in accordance with the invention are described in US. Patent No. 2,657,149, issued October 27, 1953 to R. K. Iler. The estersils are organoposed of a montmorillonite mineral in which at least a part of the cation content of the mineral has been replaced by an organic base. Clays that swell at least to some extent on being contacted with water and contain as a primary constituent a mineral of the group known as montmorillonites are generally.referred. to,as bentonites. Such clays, which contain exchangeable alkali metal atoms either naturally orafter =treatment, con9. stitute the raw materials em'ployed'in making. the hen: tonite-organic base compounds used in the compositions of this invention. So far. as known, all naturally ,oc-

curring montmorillonites contain some magnesium and certain of them, as exemplified by Hector clay, contain such a high percentage of magnesium that they largely have magnesium in place of the aluminum content characteristic of the more typical montmorillonites.

prepared as described in US. Patent No. 2,033,856,

issuedrMarch 10, .1936, by bringing together the henphilic solids made by chemically reacting primary or secondary alcohols with certain siliceous solids. In brief, the estersils are powders or pulverulent materials the internal structure or substrate of which have an average specific surface area of from 1 to 900 square meters per gram. The substrate has a surface of silicawhich is coated with -OR' groups, the coating of .-'-OR' groups being chemically bound to the silica. .R' is a hydrocarbon radical of a primary or secondary alcohol containing from 2 to 18 carbon atoms. oxygen isalso attached to hydrogenr The estersil substrates are solid inorgamc siliceous materials which contain substantially no chemically bound organic groups prior to esterification. The substrates are in -a supercolloidal state of subdivisionindicating that whatever discrete particles are present are largerthan col loidal size. In general, the supercolloidal substrates have at least one dimension of at least 150 millimicrons. The supercolloidal particles may be aggregates of ultimate The bentonite-organic base compounds are preferably units which are colloidal mvslze The estersils which we employ are advanta geo1isly those in which the ultimate unitshave an average diameter of 8 to 10 millimicrons. The substrates, 'advan V tage ously have specific surface areas of at least 2 5 sguare meters per gram and preferably at leastQOQ- Square tonite-organic base -'compoundsuused "in preparing the lubricating compositions of this invention are preferably those, prepared by bringing together a bentonite clay and such organic-"bases as aliphatic arnines,-their.salts, andrs P r 9 a 1 The estersils made from most alcohols become organo philic when they contain more than 'about esterigroups' per 1 O0:'square millimicrons of surface zojfinternaljstruce ture. They become moreorganophilic as the tester groups increase. -Thus,ithe products which containdfloester.

The carbon'atom attached to the a saess groups-per 100 square millimicrons of, substrate surface are more organophilic' than those that contain only 80 ester groups; When the estersils contain at least 200 ester groups per 100'square millimicrons of substrate. surface, the estersilsnotonly are organophilic but also are hydrophobic. Thus, the more highly esterified products are particularly desirable where the lubricant made therefrom comes in contact with water. When C toC alcohols are used in preparing the estersils, the estersils may contain from 300 to 400 ester groups per 100 square millimicrons of substrate surface. Thus, a preferred group of estersils are those prepared from the C to C alcohols. The estersils, as noted above, are powders or pulverulent materials. The estersil powders are exceedingly fine, light and fluffy. The bulk density of preferred'estersils is in the order of 0.15 to 0.20 gram per cubic centimeter at 3 pounds per square inch and in the order of about 0.30 gram per cubic centimeter at 78 pounds per square inch. The estersils are available commercially and thus the estersils per se and theirpreparation constitute no part of this invention.

The lubricating oil in which the bis-pyrazolone and the secondary thickening agent are incorporated is preferably a lubricant of the type best suitedfor the particular use for which the ultimate composition is designed. Since many of the properties possessed by the lubricating oil are imparted to the ultimate lubricating composition, we advantageously employ an oil which is thermally stable at the contemplate. lubricating temperature. Some mineral oils, especially hydrotreated mineral oils, are sufliciently stable to provide a lubricating base for preparing lubricantsjto be used under moderately elevated temperatures. Where temperatures in the order of 400 F. and aboveare to be encountered, synthetic oils form a preferred class of lubricating bases because of their high thermal stability. By the term synthetic oil We mean an oil of non-mineral origin. The synethetic oil can be an organic ester which has a majority of the properties of a hydrocarbon oil of lubricating grade such as di-Z-ethylhexyl sebacate, dioctyl phthalate and dioctyl azelate. Instead of an organic esters, we can use polymerized olefins, co-., polymers 'of 'alk ylene glycols and alkylene oxides, poly organo siloxanes and the like.

The liquid polyorgano siloxanes because of their exceedingly high thermal stability form a preferred group of f synthetic oils to which the bis-pyrazolone and organophilic siliceous materials are added. These polyorgano siloxanes are known commercially as silicones and are made up of silicoirand oxygen atoms wherein the silicon atoms may be substituted with alkyl, aryl, alkaryl, aralkyl and cycloalkyl radicals. Exemplary of such compounds are the dimethyl silicone polymers, diethyl silicone polymers, ethyl phenyl silicone polymers and methyl-phenyl silicone polymers If desired, ablend of oils of suitable viscosity may be employed as the lubricating oil base instead of asingle a.

oil by meanslof which any desired viscosity may be se cured. Therefore, dependingupon the'particular use for the ultimate composition i s designed, the lubricating oilbase' may be a mineral oil, a synthetic'oil, or a mix ture of mineraland/ or. synthetic oils. The lubricating oilc ontent of the compositions prepared according to this invention comprises about 40 to about. 90 percent by Weight of the total composition.

In compounding the compositions of the present inven- The slurry thus formed is then subjected to a conventional milling operation in a ball mill, a colloid mill, homogenizer or similar device used in compounding greases to give the desired degree of dispersion. In the illustrative compositions of this invention, the slurry was passed twice, by means of a pump, through a Premier Colloid Mill set at a stator-rotor clearance of 0.002 inch. Maximum thickening occurred on the second pass through the mill.

The lubricating composition of this invention can contain conventional lubricant additives, if desired, to improve other specific properties of the lubricant without departing from the scope of the invention. Thus, the

lubricating composition can contain a filler, a corrosion and rust inhibitor, an extreme pressure agent, an anti-oxidant, a metal deactivator, a dye, and the like. Whether or not such additives are employed and the amounts thereof depend to a large extent upon the severity of the conditions to which the composition is subjected and upon the stability of the lubricating oil base in the first instance. Since the polyorgano siloxanes, for example, are in general more stable than mineral oils, they requirethe addition of very little, if any, oxidation inhibitor. When such conventional additives are used they are generally added in amounts between about 0.01 and 5 percent by weight based on the weight of the total com-. position.

In order to illustrate the lubricating characteristics at an elevated temperature and high rotational speeds, grease compositions of the invention were subjected to the test procedureoutlined by the Coordinating Research Council Tentative Draft (July, 1954), Research Technique. for the Determination of Performance Characteristics of Lubricating Grease in Antifriction Bearings at Elevated Temperatures, CRC Designation L-35. Accord ing to this procedure, 3 grams of the grease to be tested are placed in a bearing assembly containing an eight-ball SAE No. 204 ball bearing. The bearing assembly which is mounted on a horizontal spindle is subjected to a radial load of 5 pounds. The portion of the spindle upon which the ,testb earing assembly is located is encased in a thermostatically controlled oven. By this means the temperature of the bearing can be maintained at a desired elevated temperature which in the tests reported hereinafter was 400 F. The spindle is driven by a constant belt-tension motor drive assembly, capable of giving spin dle speeds up to 10,000 revolutions per minute. The spindle is operated on a cycling schedule consisting of a series of periods, each period consisting of 20'hours running time and 4 hours shutdown time. The test continues until the lubricant fails. The lubricant is considered to have failed when any one of the following conditions occurs, (1.) spindle input power increases to a value approximately 300 percent above thesteady state .condition at the test temperature; (2) an increase in temperature atthe' test bearing of 20 F. over the test temperature during any portion of a cycle; or (3) the test bearing locks or the drive belt slips at the start or during the test cycle;

.Theoil used in preparing the lubricating composition summarized in Table I was a syntheticoil known commercially as DC 550 fluid. marketed by Dow-Corning tion, various mixing and blending procedures may be used, Ina preferred embodiment of the invention the lubricating oil-,Athe bis-pyrazolone and the secondary thickenertogether-with a solvating agentand conventional lubricant additives, :if desired, are mixed together at noo'mtemper'ature; for -a period of l0 to,30 minutes. to

, form.- ;a slurry.1...:DuIing this. initial mixing period. some thickening-:issevidenced. Some lumpsmay be formed.

Corporation. This fluid is a methylphenylsiloxane polymer having as typical characteristics a viscosity at F. of 300 to 400 SUS, a viscosity-temperature coefiicient of 0.7-5, a freezing point of 5'4 F., a flash point of 600 F. and a specific gravity 25 C./25' C. of 1.08. y Inpreparing the lubricating composition, the oil, the I 4,4'-bis( 1-phenyl-2,3-dimethyl-5-pyrazolone) and the di methyldicetylamrnonium: bentonite=.-Were mixed at room temperature for a periodof 10 to 30 minutes. The slurry thus formed was passed twice through a Premier Colloid Mill set at a stator-rotor clearance "of 0.002 inch. The thickened lubricating-composition thus prepared had the following approximate make-upand properties:

4 7 -=TABLEI.

I Composition; percent by weight Lubricating oil: v

,DC 550 fluid 66.4

drogen, alkyl, aryl, aralkyl and cycloalkylradicals, R1 is selected from .the group consisting of t'arylyaralkyl andalkaryl radicals and R" is selected fromthegroup consisting of alkyl; aryl and alkaryl radicals, :wherein "While our invention has been described-with reference to various specific examples and embodiments it will be understoodthat'the invention is not limited to such ex amples and embodiments and'may be variously practiced within thescope'of the claims hereinafter made. We'claim: .ll; A? lubricating composition comprising a dispersion in a lubricating oiljofa "sufiicient amount to thicken the lubricating oil to ,-,a, grease ;consistency-of a mixture of. a bis-pyrazolone having the: follmying structural formula:

selected 2.50 the group; consisting. of hy-- i p each of said alkyl ra'dicalscontains from; 1' to15..carbon -p y ,3-d1methyl-5-pyrazolone 30.0 atoms and, the alkyl portion of said aralkyl-and alkaryl Secondary thickener: .t e radicals contains not more than 2 carbon atoms and an v .Dimethyldicetylammoniun'i bentonite 3.6 organophilicsiliceous oil thickening agent, theweight t a t. lnspecfionratioof the bis-pyrazolone to the organophilic siliceous v H material in said mixture being about; 1:1 to about 20:1. Penetl'atloll M D2 T) 2. The lubricating composition of claim 1 wherein the UIIWOFked 1 -t----- --.----,---t--- 7305 combined bis-pyrazolone and organophilic siliceous ma: --,---c-tt-. -s--. 324 terial comprises about 10 to 60 percent byaweight of D pm ro p". F- (A T 5664 the totalcomposition. is g PFPfOYmaIICE hrs-1 v t. Lv v A 3; The lubricating composition of claim l wherein the 10,000 r.p.m. at 400 F 7 9 lubricating oil is a polyorgano siloxane. I 1 The long performance life of the composition of the T f g q po itmn of claim lwherem the invention at a high rotational speed and a high tempera- Q eem slhceous 9 t m agent m m ture is sel f'evident from the above data. 1 When this comorgamc base 9 i I position was subjected even to a more severe test using clam wherem the p- Sbindles andan MRC 204 S47 bearing at 4000 organophllic siliceous 011 thickemng agent is an organon 20,000 revolutions per minutea performance life of philic estersil comprising asupercolloidal substrate coat- 1 hours was obtained I 7 ed with OR' groups the substrate having a surface Other lubricating compositions within the scope of the of Silica having a Speclfic suifacg-ania of invention are illustrated in Table II. G.E. Silicone 81717 to 900 sqliaremeteirs m hi W 3 is marketed by General Electric Company and is a wateri bemg chgmlca g. f 2 i I white to amber liquid polymer of the general formula 126mg hydiocar m ma of t f i on T Y p orns, wherein the carbon attached to oxgen is also at- S1 (CH3)ZOSI(CH3)ZOS1(CH3)2O ]X tached to hydrogen. a 3 Ithas a viscosity at --65 F. of 3487 centistokes, at 0 F. hibri-catihg 9 compmsing ,afdispelrslon of 390.centistokes, at 100%. of 71.3 centistokes, at 210 Polymgan? 0f a suifiqent t??? F. of.22vcentistokes and at 700 F. of 1.9centistokes. to thicken j Polyorgano s1loxane to a gnajase consist: Estersiil GT is marketed'by'E. I. du Pont de Nemours 9f a mixture of a blpyrazolone having l? and Company and'consi st'sof an amorphous silica coat- 95 Strucmr a1 a? v ed with approximately 340 butoxy groups per 100 square R" (I3:0- Cm w millimicrons of surface. The product'is a white granu- 21:0 0:41 NTR lar solid comprising 8810- 89 percentSiO having an; ultimate particle size of 8 to 10 millimicrons'Q The surp face area comprises about 285 to 335 square meters per 40 v A i c gram. The product has a pH in a -50 methanol wherein R is selected from thegroup consisting of hywater mixture of 8.0 to 9.0 and abulk density of 19 drogen; alkyl, aryl,aralkyl and cycloalkyl radicalsrk to 20 pounds per cubic foot; 7 1 is selected from the group consisting of .aryl,', aralkyl Table 11 Oomposltlon,- Percent By Weight I A 1B p E F G H I J- K L M N 5 O Lubricating on: i v

DC 550 Fluid "64 70 70 64 64 G.E. Silicone 81717 47.5 70 so 70 70 Di-irethylhexylsebacate v V 60 64 60 Bis pyrazolone:

Le-bis(1 phenyl-3-methyl-s-pyrazolona) 24 20 4-4-bis(l-naphthyl-3-methyl 5-pyrazol0ne). 24 25 4,4-bis(1-toly1 3-methyl-5-pyrazolone) 82 10 35 4,4-bis(1-pheuyl-2,3-diethyl-fi-pyrazolone) 32 30 50 20 30 '-25. 32 36 Secondary Thickener: v- V 3- Dimethjldicetylammonium bentonite- :s! 4 4 Dimethyldidodecylammonium bentonite 6 5 'Dlmethyldioctylammonium bentonite.' 6 10 g j Dimethyldioctadecylammonium bentonite 5" Estersil GT 4 A 4 Ratio of bispyrazolone to secondary thickener 4:1 5 21 7:1- 3:1 551. W 8: l 9:l

and alkaryl radicals: and R is selected from the group consisting of alkyLfaryl and 'alkaryl radicals, wherein each of 'said alkyl radicals contains from 1 to 5 carbon atoms and the alkyl portion of said'aralkyl and alka-ryl radicals'containsnot more than 2 carbon atoms and an organophilic 'bentonite-organic 1 'base compound, a the weight ratio of the bis-pyrazolone to the organophilic bentonite-organic-base compound in said-mixture being about'1:l toabout 20:11 e

The lubricating composition ofclaim 6wherein' theF-bis-pyrazolone is 4,4'-bis(1-phenyl-2,3 dimethyl 5- py'ra'zolone) and the bentonite-organic" base comp u d} is dimethyldicetylammonium bentonite. 2 8; A lubricating composition comprising f a dispersion in a: liquidipolyorgano 'siloxane of a suflic'ient amount 7 to thicken Ithe. polyorgano siloxane to a grease consist ency of a mixture of a bis-pyrazolone having the following structural formula:

wherein R is selected from the group consisting of hydrogen, alkyl, aryl, aralkyl and cycloalkyl radicals, R is selected from the group consisting of aryl, aralkyl and alkaryl radicals and R" is selected from the group consisting of alkyl, aryl and alkaryl radicals, wherein each of said alkyl radicals contains from 1 to 5 carbon atoms and the alkyl portion of said aralkyl and alkaryl radicals contains not more than 2 carbon atoms and an organophilic estersil, the weight ratio of the bis-pyrazolone to the organophilic estersil in said mixture being about 1:1 to about 20:1, said organophilic estersil comprising a supercolloidal substrate coated with OR groups, the substrate having a surface of silica and having a specific surface area of from to 900 square meters per gram, the coating of OR' groups being chemically bound to said silica and R being a hydrocarbon radical of from 3 to 6 carbon atoms, wherein the carbon atom attached to oxygen is also attached to hydrogen.

9. The lubricating composition of claim 8 wherein the bis-pyrazolone is 4,4 bis(1 phenyl 2,3 dimethyl 5-pyrazolone) and the organophilic estersil is an amorphous silica coated with about 340 butoxy groups per square millimicrons of surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,655,476 Hughes et a1. Oct. 13, 1953 2,711,393 Hughes et a1. June 21, 1955 2,766,209 Marshall et a1 Oct. 9, 1956 

1. A LUBRICATING COMPOSITION COMPRISING A DISPERSION IN A LUBRICATING OIL OF A SUFFICIENT AMOUNT TO THICKEN THE LUBRICATING OIL TO A GREASE CONSISTENCY OF A MIXTURE OF A BIS-PYRAZOLONE HAVING THE FOLLOWING STRUCTURAL FORMULA: 